Inteknal-gbinding machine



' J. G. MDONOUGH INTE RNAL GRINDING MACHINE 15 Sheets-Sheef 1 originalFiled on: 31, 1921 v gwuenl'oz 6', m gponou abbey: m1;

Aug. 11, 192s. v 7 Re. 16,141

J. a. M DONOUGH INTERNAL GRINDING MACHINE Original Filed Oct. 51, 192115 Sheets-Sheet :s

' 1x24 lz a z79 I I v Aug. 11, 1925'. V Re;"i6,141

J. G. M DO NOUG H INTERNAL GRINDING MACHINE Original Filed Oct. 31, 192115 Sheets-Sheet 4 FIG. 4.

' gwmznlom i LZSe ZI amp lfza ql Y 2 Aug. 11, 1925; Re. 16,141

J. G. McDONQUGH INTERNAL GRINDING MACHINE Original Filed Oct. 51, 1921l5 Sheets-Sheet 5 gmw/nl oz 'Aug 11,1925. 1 Re. 16,141.

' Y J. G. M =DONOUGH I INTERNAL GRINDING MACHINE ori inal ile 0st. 31,1921 15' Sheets-Sheet a .G am.

Aug. 11, 1925.

, 1 I Re. 16,141.

J.-G. MGDONOUGH 11111111111111 GRINDING 111101111111 I 7 Original FiredOct. 1921 15 Sheets-Sheet 7 Gra l?) Gib/whom .Aug} 11, 1925 v v J. G.MODONOUGH INTERNAL GRINDING MACHINE 15 Shets-Sheet s j Jase/,7, 6107sOriginal Filled Oct. 31, 1921 15 Shee'ts-Sheet 9 l 3 m WiZbwyZ,

26 I 288 Jase 1% 6- 7 N d I I z 15 Sheets-Sheet 10 J. G. M DONOUGHINTERNAL GRINDING MACHINE Orizinal' Filed Oct. 31, 1921 Gamma Aug. 11',1925. Re, 16,141

. J. G. MDONOUGH INTERNAL GRINDING MACHINE Original Fil'ed Oct. 31, 192115 Sheets-Sheet 11 85w a4 62 g 6/. a; a;

' 27/ 27 5 we a? amnion Jive 71 617 Aug. 11, 1925. 1 Re. 16,141

J. G. M DONOUGH INTERNAL GRINDING MACHINE zinal Filed Oct. 51, 1921 I 15Sheets-Sheet 12 Joke 27o G. Willa/Map? Aug. 11, 1925. [16,16,141 J. G. MDONOUGH INTERNAL GRINDING MACHI NE Z674 v Z? Aug. 11, 1925. Re. 16,141

' G. M DONOUGH INTERN L GRINDING MACHINE ONiginal Filed Oct. 31, 1921 1SSheets-Sheet 15 rlllllllllllI/l Reissued Aug. 11, 1925.

uniT-ED STATES PATENT OFFICE.

INTERNAL-GRINDING MACHINE.

Original No. 1,497,574, dated June 10, 1924, Serial 161"511516, filedOctober 31, .1921. Application for reissue filed January 21, 1925.Serial No. 3,884.

To all whom it may concern:

Be it known that I, JOSEPH G. MCDON- oUGn, a citizen of the UnitedStates, resident of New Orleans, Orleans Parish, State of Louisiana,have invented certain new and useful Improv ements in InternaLGrindingMachines, of which the following is a specification.

My invention relates to machines for grinding the internal surfaces ofmetal cylinders, sleeves, gears, bushings, and the like commercialarticles and the general object of the invention is to provide a machinethat is capable of turning out rapidly and cfiiciently products of'thisclass in cylindrical, conical and other forms, ground and finisheduniformly to within the closest limits of the predetermined finisheddiameters, and that will automatically cease the grinding operation whenthis diameter has been attained or announce the fact to the operator, orboth, and that will, furthermore, indefiiitely continue this operationwith the same accuracy and uniformity of output regardless of the wearofthe grinding wheel.

More specific objects of the invention are:

First: To prevent the usual bell mouthing which consists in aperceptible outward fiarc at the ends of the internal cylindricalsurface being ground, due to the necessity of repeated withdrawal of thegrinding wheel from the cylindrical bore for the purpose of calibratingthe internal diameter or introducing a gage plug.

Second: To eliminate the usual so-called sagging resulting in inaccuracof the work and due to overhanging wor -holding chucks or other fixturesin the ordinary horizontally operating internal grinding machines.

Third: To do away with the necessity of measuring the work during theprogress or at the finish of the grinding, while at the same timeautomatically obtaining vwithin close limits extremely accurate resultsin finished measurements.

Fourth: 'lo automatically preserve practically the same high degree ofaccuracy both when grinding dry or wet or when grindingat dilfercnt orvarying temperatures. -1n the ordinary practice of gaging the work, thevarying temperature of the pieces ground when gaged results ininaccurate measures when the work cools off to normal temperature aftergrinding.

Fifth: Toaccelerate the work and reduce the attendance necessary byautomaticallystarting the grinding of a piece at an increased or heavierspeed to remove more stock for each passage of the grinding wheelthrough the piece and then automatically reduce the feed to remove lessstock during the final finishing operations.

Sixth: To make the feeds positive to the predetermined degree of feed bypreventing the usual lost motion or play in the feed mechanism.

Seventh:- To provide a machine of the multiple spindle type that willrequire but little attendance and that by its large ca pacity andrapidity and accuracy of action will enable the user of the machine tomanufacture the finished articles cheaply and economically.

Other objects of the invention will appear from the followin detaileddescription of the invention by reference to the accompanying drawings.

In the accompanying drawings forming part of this specification,

Figure 1 is a side elevation, partly in section, of a machine embodyingmy invention,

Figure 2 is a plan and sectional view of a multiple spindle machineembodying my invention, and consisting of six spindle units, four ofthese units being removed and the left hand unit being shown inhorizontal section on the line 2" and the right hand unit section on theline 2 of Figure 1,

Figure 3 is a front elevation of one of the spindle units,

Figure 4 is a rear elevation of one of the spindle units,

Figure 5 is a horizontal sectional view on the line 5-5 of Figure 4,

Figure 6 is a side elevation on a larger scale of one of the spindleunits, showing the spindle carriage in a lowered position,

Figure 7 is a ccntralvertical section of the spindle unit as shown inFigure 6,

Figure 8 is ahorizontal section on the line 88 of Figure 1, showing thefeed screw mechanism,

Figure 9 is a vertical section on the line 9-9 of Figure 8,

Figure 10 is a vertical section of the feed screw operating mechanism,the section be ing taken on the line 10-10 of Figure 12,

Figurell is a vertical section on the line ll-llof Figure 10,

Figure 12 is a similar section on the line 12-12 of Figure 10,illustrating the electrically controlled feed mechanism,

Figure 13 is a partial sect-ion on the line 13-13 of Figure 10,illustrating the adjusting means for the feed,

Figure 14 is a vertical section through the gage supporting chuckspindle and electric control housing below the spindle,

Figure 15 is a section on the line 15-15 of Figures 14 and 16,

Figure 16 is an enlarged section on the line 16-16 of Figure 14,

Figure 17 is a section on the line 17-17 of Figure 14,

Figure 18 is a section on the line 18-18 of Figure 19, of the spindlechuck for bold ing the pieces to be ground and illustrating the methodof gaging the work,

Figure 19 is a plan view of the chuck, partly in section, on the line19-19 of F igure 18,

Figure 20 is an enlarged vertical section of the switch box shown inFigure 14 for controlling the vertical movements of the grinding wheeland its carriage,

Figure 21 is a cross section on the line 21-21 of Figure 20,

Figure 22 is a detail view of the carriagecontrolling clutch-mechanism,illustrating in v and work when grinding a tube and diagrammatical formthe electrical connections between the clutch mechanism and the switchbox,

Figure 23 is a detail of the adjustable trip blocks,

Figure 24 is a vertical section of the grinding wheel and stationaryguard, illustrating the relative position of the gages automaticallychanging from a coarse to a fine feed, the grinding wheel beingindicated as moving upward,

Figure 25 is a plan view of Figure 24,

Figures 26 to 31 inclusive illustrate modified forms of gage pins andmeans for securing said pins in accurate positions in the gage post,

Figure 31 shows a form of when grinding short articles,

Figure 32 is a perspective view generally preferred form of Figure 33 isa diagrammatical view, illustrating the general automatic control andoperation of the machine,

Figures 34, 35 and 36 are similar views, illustrating the automaticelectrical control of the spindle carriage and showing the parts indifferent positions,

gage pin used of the gage pin,

spindle may readily be ground perfectly concentric to the bearings afterfastening,

Figure 39 shows a modified form of gage post and means for protectingthe post from water when used in a horizontal grinding position.

The driving and grinding mechanism.

In Figures 1 and 2 I have illustrated my invention as comprising amultiple spindle machine, but it will be understood that the claims ofthe invention are not confined to this construction, as each spindlesection in itself is a complete, self-contained grinding unit capable ofindependent operation.

\Vhile I have illustrated in the drawings a multi-spindle grindingmachine of a circular type, it will also be understood that the grindingspindles may be arranged in banks or rows or any other convenient formand that theinvention is not confined to the multi-spindle feature butis mainly embodied in the novel construction and operation of each ofthe single grinding units.

Referring first to Figures 1 and 2 for an illustration of theconstruction and operation of the multiple spindle feature of themachine, it will be noted that the base frame 20 supporting thestructure comprising the six spindle units is rotatable upon thecircular track 21 of the main bed frame 22. Integral arms 23 projectfrom the base frame 20 to which are secured vertical brackets 24carrying at their upper ends flanged rollers 25 adapted to roll on thetrack 21 and support the whole operating structure. A beveled ring gear26 is rigidly secured to the Vertical brackets 24 and meshes with abeveled pinion 27 carried b a shaft 28, that is journaled in suitablebearings in th housing 29 and is also provided with a friction disc 30.A driving shaft 31, having a wheel 32 in frictional engagement with thedisc 30 and a driving pulley 32, is

journaled transversely to the shaft 28 in with the rack 39. Motive powermay be applied from any suitable source to the drivmg pulley 32 whichwill transmit motion I through the shaft 31 and friction members 30 and32 to the shaft 28. Suitable planet'ary' reduction gearings 43 may bearranged in connection with the shaft 28, but this as well as thedriving mechanism above debeveled pinion 27 rotate, the base frame 20and the superstructure carried by it will be caused to rotate by meansof thering gear 26 and that the rotat' speed of the structure may bevaried as esired by operating the hand wheel 41, sliding rack bar 38 andthereby adjusting the friction wheel 32 on the frlction face of the disc30, to any desired position. The mechanism comprising each of thgrinding units is mounted in the vertical frames or columns 44, that areat the bottom secured to the base frame or plate 20, preferably by boltsor screws 45, and are rigidly secured together at the top by the spiderplate 46 and screws 46".

intermediate frame or housing 47 is secured to the vertical framemembers 44, preferably by lugs 47' and screws 48, and a central or amaster shaft 49 is journaled in this frame below and has bearings 50above in the spider plate '46. This shaft 49 may be driven in anysuitable manner, preferably by an electric motor (not shown) and drivesthe entire mechanism of all the grinding units through suitable speedchange gearing 51 in the housing 47. As the construction and operationof all the grinding units operated'by this master shaft are identical,

the following description pertains equally to all the units.

A vertical shaft 52 provided with speed change gearing 53, meshing withthe gearing 51, is mounted in bearings in the housing 47 and carries atits lower end a pulley 54, the function of which will hereinafterappear. The speed-change for this shaft is effected preferably by meansof a sliding key (not shown) in the shaft 52 operated through a rod 55by a hand lever 56, but as this mechanism forms no art of the inventionand any method 0 efi'ecting s eed changes from the shaft 49 to the sha t52 may be employed, I have not illustrated the details of this speedchange mechanism.

The column 44 is provided with horizontal V-flanges or tracks 57,accurately fit tingcorresponding riders 58 in a lateral feed block orsaddle 59 by means of which said saddle is supported capable of ahorizontal movement relative to the column 44. A hollow spindle 60 isjournaled in bearings 61 and 62 upon abearing-head 59 adjustably securedto the saddle 59 ina'circular slot 61 (Fi re 9) by means of slot bolts59 and carries a pulley 63 on ahorizontal line with the pulley 54. Aseries of flexible belts 64 pass'from the pulley 63 through a slot 65 inthe column 44 around the pulley 54 by which the spindle 60 is startedwithout shocks from the shaft 52 and rotated primarily from the mastershaft 49.

The spindle 60 carries on its upper end a cylindrical chuck 66 supportedon a flange 67 of the spindle and this chuck is provided with universalclamping means for accurately centering and holding the tube or othercylindrical work piece '68 or piece to be ground (see Figures 18 and 19). The clamping means preferably consists of three hardened clampingsegments 69 removably 70 by screws 71. The work-piece 68, when insertedin the clamp ring, rests on a slightly protruding flange 72 at thebottom of the ring segments and these segments may be removed and otherssubstituted of a different internal radius to fit different size tubesto be ground. The wedge blocks 70 '80 fastened to three segmental wedgeblocks are formed externally conical, fitting the internalv conicalsurface 73 of the chuck 66 and when the tube 68 is to be inserted, theblocks 70 are raised, to spread or expand the ring segments 69, thesesegments being 1 under constant spreading tension by means of coiledsprings 74 inserted in the end of the segments between their separatedjoints, (Figure 19). been inserted, all the segments comprising theclamp unit are forced downward, thereby uniformly contracting the ringsegments and centering and securely clamping the piece in place. Thevertical adjustment of the clamp members is preferably effected by meansof an internally threaded sleeve 75 having a flange 76 engaging acircular groove 76 in the wedge blocks 70 and being in threadedconnection with the external threads of the hub of a gear wheel 77loosely mounted upon a central boss 78 of the chuck 66 for rotation, butheld against vertical displacement by a ball 78 in an annular groove78*. Spindles 79 carrying pinions 7 9 in mesh with the gear. wheel 77are arranged in the rim of the chuck and project to the top thereofwhere they are provided with hexagon or equivalent shaped heads 80. Bymeans of a wrench applied to any one of thespindle heads, the gear 77may be rotated in either direction, thereby forcing the sleeve 7 5 andwedge blocks 70 up or down to release therefrom, or clamp the ringsegments tightly'around the work piece 68 (Figures 18 and 19). The

grinding wheel 81, consisting of emery, car- 1 After the work-piece 68has vertically in bearin s 84 and 85 arranged within a dust proo?housing 85 provi ed in a frame or carriage 86 that is verticallyslidable in V-slots 87 in the column '44 (see Figure 2). The arbor 82 isprovided at its upper end with'a driving pulley 88 and an anti-frictionthrust bearing 89 and is driven at high s eed from the master shaft 49by means 0 a pulley 90 frictionally engaging a pulley 91 fastened to avertical roller pulley 92, said pulley being mounted upon a shaft 93-having upper bearings 94 and lower adjustable bearings 95, arrangedupon the column'44 (Figure. 1). A driving belt 96 runs from the rollerpulley 92 through slots in the column 44 and around a small pulley 97carried by. a 98 journaled in ball bearings 99 and 100 in a housing 101integrally connected to the carriage 86 by a bracket or arm 102 (Figure7). A larger pulley 103 is preferably cast integral with the smallpulley 97 and a belt 104 runs from this pulley around the arbor pulley88. Frictional tension is provided between the friction pulleys 90 and91 by means of a coil spring 105 arranged in a socket 105 in the column44 and tensioned against the bearing block 95, that is mounted for aslight lateral movement between the guide lugs 106 (see Figure 7). Iprefer to provide means for temporarily throwing the friction wheels outof engagement consisting of a lever 107 pivoted on one of the guide lugs106 and aving a pin 108 normally free of the bear ing block 95 but whenthe lever 107 is rocked towards the block by means of a rod 109 having ahandle 110 (see Figure 2), the block" 95 may be moved slightly againstthe tension of the spring 105 to release the friction wheel 91 from thedriving wheel 90 and sto'protation of the roller pulley 92.

In the operation of grinding a tube or cylinder to an exactpredetermined internal diameter, the rotating grinding wheel isautomatically and repeatedly passed downwards and upwards in grindingcontact with a small arc of the internal surface of the cylinder untilthe predetermined internal diameter is attained. The chuck 66 containingthe cylindrical work-piece to be ground simultaneously rotates in theopposite direction, driven by the belt 64. At the conclusion of eitherthe downward or upward movement of the grinding wheel 81 or at both endsof the movement, as will be hereinafter described, the saddle 59carrying the chuck 66 is automatically moved laterally in the directionof the grinding wheel to again bring the work-piece in active grindingcontact with the grinding wheel.

When the piece has been finished tothe required internal diameter, the.grinding short spindle boss 118 concentric with the bearing. sleeve 119having a forked projection 120 gear 134 (Figures 1, 4

wheel 81 is automatically raised to a higher plane above the chuck 66and preferably continues to operate idly at the higher plane while thefinished. piece is being removed and a fresh one inserted in the chuck66- The vertical reciprocating movement in different planes of thecarriage 86, carrying the arbor for .the grinding wheel 81, is obtainedpreferably by the hereinafter de scribed means. Referring to Figures 3.and 7, a screw shaft or Worm 111 is slidably mounted at its lower end ina lug 112 of the carriage 86- and is provided with a nut 114 below thelug 112. .The worm passes through an internally threaded hub 115, of abevel gear 116 that is rotatably mounted in a bearing on the column 44,and is provided at the lower end of the hub with a thrust c'ollar 115;The carriage is provided at its upper end with a bracket 113 having a Aslidably fits the boss 118 and a pin 121 passes through holes in theshaft 111 and sleeve 119 and through a slot 122 in the boss 118.

The forked end 123 of the projection embraces a lever 124 pivoted at 125to a lug on the bracket 113 and having on its opposite end a slot 126engaging a pin 127 that is carried by a vertical trip bar 128 supportedin bearings 129 and 129 upon the carriage 86 and capable of a limitedvertical adjustment. The screw shaft 111 is prevented'from rotating bythe pin 121 and it will be seen that as the bevel gear 116 is rotated inthe bearing 117 the shaft 111 will be moved vertically in the threadedhub of the gear 116 and that the carriage 86 will be moved up or down,accordingly as the gear is rotatedin one or the other directionsRotation is imparted to the gear 116 by the bevel gear 130 secured on ashaft 131 and meshing with the gear 116 and this rotation isautomatically reversed at the end of each vertical movement of thecarriage 86 by the following described mechanism. The shaft 131 to whichthe bevel gear 130 is secured is preferably rotatably mounted in abearing 132 carried by a bracket 46 depending from the spider 46 andcarries a larger spur gear 133 keyed thereto. This gear is in mesh witha spur and 5) keyed .or otherwise secured to a shaft 135 that is mountedin bearings 136 and 137 on the column 44 and carries bevel gears 138 and139 running loosely thereon. The bevel gears 138 and 139 are in constantmesh with a small bevel gear 140 upon a shaft 141 journaled in bearingsin the column 44 and provided at its outer'end with another bevel gear142 in mesh with a similar car 143 upon a vertical shaft 144 havingcolumn 44 and provided at its lower end with a universal coupling 146(see Figures 4 and7). A tumbler rod 147 connects this.

earings upon the t e speed change shaft 52. Through the above describedtransmission mechanism the bevel gears 138 and 139 are caused to rotatein opposite directions upon the shaft'135,

ese gears are provided with clutch teeth 138 and 139" respectively seeFigures 5, 6, 22, 33, 34 and 36) and a c utch collar 152 havingcorresponding clutch teeth to in-. terlock with the teeth .138 and 139,isarranged between the gears 138 and 139 and is slidmgly splined to theshaft 135 to rotate therewith. It is obvious that if the clutch collar152 is brought in engagement with the clutch teeth of the gear 138, thegear 116 will be revolved in a predetermined direction and if the clutchcollar is connectedto the clutch teeth of the gear 139 the gear 116 willbe revolved in the opposite direction and that the carriage 86 w1ll bemoved in corresponding opposite vertical directions.

.Clutch connection is shifted alternately between the gears 138 and 139caused by, the vertical-travel of the carriage 86by means of a bellcrank lever 153 (see Figure 6) fulcrumed at 154 on the column 44 andengaging with considerable axial play an annular slot 155 in the clutchcollar. The lateral arm 153" of the bell crank lever is alternatelystruck at the termination of the carriage travels, by tripblocks 156 and157, thereby rocking the lever on its fulcrum and moving the clutchcollar from connection with one .to the other of the ears 138 and139.The lever 153 is prefera 1y provided witha depending arm 158 engaged bya springpressed latch 159 slidingly arranged in abracket 160, the armand latch having'beveled interlocking ends for tripping and holding thelever 153 in either extreme position with the clutch collar 152 inengagement with one of the gears 138 or 139. The trip blocks 156 and 157are vertically adjustable on the bar 128 (Figure 23) to adjust thetravel of the carriage to various lengths of grinding work. Adjustment-of the travel of the carriage to close limits may be readilymade by adjusting the actuating screws 1631 in the blocks 156 and 157.

I The lateral feed or setting up mechanism The work-carrying chuck 6.6and chuck spindle 60, as above described, are mounted part of an inch tosecure the 'required curacy, means are providedwhereb the net-' I uralslack in the motion transmitting screw;

is compensated for. I

Referring first to Figu'i' and 9, the feed screw200 is mounted in agrbearing in th'e column 44 and is provided with a drivingbevel gear202,keyed to "the shank vof the screw and rigidl held against shoulder1203 by a threa ednut 204. Thel flfi' faced back of the gear 202 {15held to against the faced end of the bearing 201 by a coilsprin 205arranged in a socket in the bearing an tensioned against a collar 206held against longitudinal movement on the feed screw shank. The threadsof the feed screw 200 fit internal threads in 9. lug 208 integral withthe feed block 59 and also with the internal threads o'f-a-follower nut209. This nut is 'free-toslide with the feed block but is prevented fromturnin by bearingagainst a face 210 on the feed b ock.

A coil spring 211 is interposed between the lug 208 and nut 209 andkeeps the threads of the lug against the drivingsideof the screwthreads. The feed screw 200 is rotated by means hereinafter described tomove the? feed block 59 in the direction of the arrow in Figure 8 whenfeeding the work against the grinding wheel and it will be seen that anyplay in the screw threads or back lash in the screw is effectuallyprevented by this construction. A ton e 212 (Figure 1) of the ringformed bearing block 59 projects into the circular groove of the feedblock and by reason of this construction, the chuck-carrying spindle 60may be readily adjusted for any desired alinement and secured in placeby the clamping bolts 59 (Figures 8 and 9). The feed screw 200 isoperated through a vertical shaft 213 mounted in bearings on one side ofthe column 44 and carrying at its lower end a small 'bevel gear 214 inmesh with the feed screw gear 202 and at-its upper end a bevel gear 215(see Figures 3, 10 to 13) in mesh with a bevel gear 216 carried by ashaft 217. This shaft is mounted in bearings 218 in a bracket 219 thatis fastened to the side of the column 44 (Figure 7 A handwheel 220 iskeyed to the outer end of the shaft 217 and i 221. Between the yoke arms221' and journaled therein, is a worm 222 provided with a knurled'fingerrip 223. A sleeve 224 surrounds the sha 217 and this sleeve is providedat its outer end with a worm wheel

